Jrreferee,
I know what it is like to be yelled at/bullied by coaches when you are a young referee. I think jbfould's comments were very good. Don't allow coaches to walk over you, let them know you are in command of the game. I was having a discussion about a similar event with a high level ref, where I was letting a player talk at me (dissent really) but I let it go. He told me that in that my particular situation it would have been a good idea to stop the game and deal with it right away for game control.
Always be polite, but be firm and get your message across quickly, caution if necessary, was his "expert" advice.
